This Independent Scientist Award (K02) application is designed to support the development of expertise in advanced quantitative methods, which will be applied to NIAAA-funded research in the areas of behavioral pharmacology and psychiatric taxonomy. Both areas of research are directed at understanding the development of alcohol problems in adolescence and young adulthood. The applicant has been productive, obtained independent funding, and established collaborative relationships in both areas. Career development will include collaboration with alcohol and drug researchers who are expert in particular quantitative procedures. Areas of quantitative skill development were chosen based on their ability to address important theoretical and conceptual issues in ways that traditional statistical techniques cannot. The applicant will gain expertise in powerful techniques relevant to psychiatric taxonomy, including Survival-Hazard Analysis, Confirmatory Factory Analysis, Item Response Theory, and Meehl s (1995) taxonomic MAXCOV-HITMAX. In both adolescent and adult data sets, these methods will be used to contrast the validity of existing systems such as the DSM-IV and ICD-10 with a new model of the diagnosis and taxonomy of alcohol use disorders. In this developmental model, abuse and dependence diagnoses represent milder and more severe manifestations of the same core addiction constructs. In the applicant s behavioral pharmacology research, mathematical modeling techniques from psychophysics will be used to characterize time-dynamic tonic and phasic components of responses to alcohol, which are sensitive to blood alcohol levels and the rate of change in these levels, respectively. These methods will be compared with other methods of assessing acute tolerance to alcohol. It is predicted that compared to controls, young adults with a family of history of alcoholism will show responses to alcohol that are primarily phasic in nature. This award will allow the applicant protected time to sustain programmatic lines of alcohol research, and will maximize the quality of his scientific contributions over the long term.